File management tools for the aufs file system.

Tools:
* aufs-find: Find files by the number of versions they have.
* aufs-list: Find all versions of a file in different branches.
* aufs-clashes: Find all file clashes between numbered branches.
* aufs-diff: Find the diff between versions of a file in two branches.
* aufs-revert: Delete the uppermost writeable version of a file.
* aufs-unwh: Remove whiteout deletion files for a path.